In the manufacture of glass containers, molten glass is molded in so-called individual section (IS) machines to form hot containers. The hot containers are placed by the machine sections on an endless belt conveyor, on which the containers are conveyed to an annealing lehr. Within the lehr, the containers are annealed for stress relief, and begin to cool. From the lehr, the containers are conveyed to various cold-end equipment for inspection, packaging etc. The lehr thus effectively divides the "hot end" from the "cold end" of the manufacturing process. U.S. Pat. No. 4,762,544 illustrates the glass manufacturing process described above.
It is proposed in U.S. application Ser. No. 08/856,829 filed May 15, 1997 to inspect glass containers at the hot end of the manufacturing process by means of optical inspection equipment disposed between the IS machine and the annealing lehr. It is difficult to calibrate such inspection equipment, however, because of the speed of movement of the conveyor and the high temperature of the glassware. Hot glassware is highly susceptible to damage due to physical contact, and it is important that glassware to be used for calibrating the inspection equipment not be damaged during the sampling process. It has been proposed as in U.S. Pat. Nos. 4,354,865 and 4,421,542 to remove glassware from the endless conveyor at the hot end of the manufacturing system by directing a jet of air onto selected containers for propelling the containers down a chute or the like. However, for calibration of inspection equipment, the likelihood of damage to the containers renders such a technique undesirable.
It is therefore a general object of the present invention to provide an apparatus, method and system for selectively removing hot articles of glassware from the conveyor at the hot end of the manufacturing system without damaging the glassware. Another and related object of the present invention is to provide a method of calibrating hot-end glassware inspection equipment that includes facility for selectively removing glassware for calibration purposes without physically damaging the sampled glassware.
Apparatus for selectively removing and holding hot glassware from a conveyor between a glassware manufacturing machine and an annealing lehr in accordance with a presently preferred embodiment of the invention includes an air jet for selectively propelling an article of glassware on the conveyor in a direction lateral to motion of the conveyor. A hot container catcher or trap is disposed on a side of the conveyor opposite the air jet for receiving a glassware article propelled from the conveyor, and for progressively engaging the glassware article so as to resist and arrest motion of the article. The glassware article is then held in position until removed by an operator. In the preferred embodiment of the invention, the article of glassware removed from the conveyor is progressively engaged by a plurality of interdigitated flexible curved vanes that are so disposed with respect to each other as to progressively increase resistance to motion of the glassware article through the vanes. The article of glassware is brought to rest over a perforated plate adjacent to a back wall, from which the article may be removed by the operator.
A method of sampling hot glassware following inspection of the glassware as the glassware moves along a conveyor between a forming machine and an annealing lehr in accordance with another aspect of the present invention includes the steps of identifying an article of glassware to be removed from the conveyor, and engaging the article with a first force lateral to the conveyor when the article reaches a preselected position along the conveyor. The article so engaged and removed from the conveyor is then engaged with a progressively increasing second force opposite to the first force so as to arrest motion of the article without damaging the article, and the article of glassware is then held in position for removal by an operator. A method of calibrating the inspection equipment in accordance with a third aspect of the invention thus includes the steps of identifying at the inspection equipment an article of glassware having a property to be calibrated, and then removing that article from the conveyor such as by directing an air jet onto the article from a direction lateral to the conveyor. The article enters the trap of the present invention, within which it is engaged by flexible vanes for progressively increasing an arresting force on the article and bringing the article to rest within the trap without damage. The article was then inspected so as to calibrate the inspection equipment.